Protein kinases are enzymes that serve as key components of signal transduction pathways by catalyzing the transfer of the terminal phosphate from adenosine 5′-triphosphate (ATP) to the hydroxy group of tyrosine, serine and threonine residues of proteins. As a consequence, protein kinase inhibitors and substrates are valuable tools for assessing the physiological consequences of protein kinase activation. The overexpression or inappropriate expression of normal or mutant protein kinases in mammals has been demonstrated to play significant roles in the development of many diseases, including cancer and diabetes.
Protein kinases can be divided into two classes: those which preferentially phosphorylate tyrosine residues (protein tyrosine kinases) and those which preferentially phosphorylate serine and/or threonine residues (protein serine/threonine kinases). Protein tyrosine kinases perform diverse functions ranging from stimulation of cell growth and differentiation to arrest of cell proliferation. They can be classified as either receptor protein tyrosine kinases or intracellular protein tyrosine kinases. The receptor protein tyrosine kinases, which possess an extracellular ligand binding domain and an intracellular catalytic domain with intrinsic tyrosine kinase activity, are distributed among 20 subfamilies.
Feline McDonough Sarcoma (FMS) is the receptor-tyrosine kinase responsible for cellular response to colony stimulating factor-1 (CSF-1). CSF-1 is the primary growth factor for the macrophage/osteoclast lineage. Inhibitors of FMS kinase reduce macrophage survival in tissues and osteoclastogenesis in bone. Accordingly, diabetes, angiogenesis, psoriasis, restenosis, ocular diseases, schizophrenia, rheumatoid arthritis, cardiovascular disease and cancer are exemplary of pathogenic conditions that have been linked with abnormal protein tyrosine kinase activity.
4-Cyano-N-[2-(4,4-dimethylcyclohex-1-en-1-yl)-6-(2,2,6,6-tetramethyltetrahydro-2H-pyran-4-yl)pyridine-3-yl]-1H-imidazole-2-carboxamide exhibits an inhibitory activity against FMS to treat diseases where macrophages and osteoclasts are pathogenic, namely rheumatoid arthritis and cancer metastasis to bone.
There remains a need to provide alternate forms of 4-cyano-N-[2-(4,4-dimethylcyclohex-1-en-1-yl)-6-(2,2,6,6-tetramethyltetrahydro-2H-pyran-4-yl)pyridine-3-yl]-1H-imidazole-2-carboxamide.